Ortho-hydroxycarboxylic acids of the diphenylene series



Patented Feb. 6, 1940 ORTHO-HYDROXYCARBOXYLIU ACIDS OF THE DIPHENYLENESERIES Friedrich Muth, Leverkusen, Germany, assignor to General Aniline& Film Corporation, a corporation of Delaware No Drawing. Originalapplication September 25,

1933, Serial No. 690,951. Divided and this appiication December 13,1935, Serial No. 54,320. In Germany October 5, 1932 a 1 Claim. (01.260-327) The present invention relates to new orthohydroxy-carboxylicacids of the diphenylene series, more particularly it relates tocompounds of the general formula:.

wherein :2 stands for S, S0 or S02.

In accordance with the present invention the. compounds of the aboveidentified formula are prepared by starting with the corresponding 3-hydroxydiphenylene compounds and treating them according to thesynthesis of Kolbe in the presence of an alkali, or in form of an alkalimetal salt thereof, with carbon-dioxide under superatmospheric pressureand at elevated temperature.

From the chemical behaviour of my new carboxylic acids results that thecarboxylic acid group stands in ortho-position with respect to thehydroxy group, and from my present knowledge I assume that it hasentered the 2-position; I wish it to be understood, however, that, incase the carboxylic acid group should have entered the other positionortho with respect to the hydroxy group, that is the 4-position, thesecompounds are falling within the scope of my invention.

The starting 3-hydroxy compounds are 0b- -tainable for example, bytreating the corressponding 3-chloro-compounds with caustic aqueousalkali at elevated temperature and under superatmospheric pressure, orby diazotizing the corresponding 3-amino-compounds and boiling the diazocompounds obtained therefrom in the presence of phosphoric acid. v

My new ortho-hydroxycarboxylic acids are generally water-insoluble moreor less yellow colored substances, soluble in aqueous alkalies andorganic solvents and are valuable intermediate I products in themanufacture of dyestuffs.

The invention is illustrated by the following r examples, without beingrestricted thereto:

Example 1.--20 parts by weight of 3-hydroxyphenylenesulfide aretransformed into the sodium salt and treated with carbon-dioxide undersuperatmospheric pressure at 210-220 C. during 8-49 hours. Aftercooling, the carbon-dioxide is removed, the content of the autoclave isdissolved in hot water and-filtered. On cooling, from the filtratecrystallizes the sodium salt of the3-hydroxydiphenyleneoxide-Z-carboxylic acid in needles. The salt isfiltered with suction,

again dissolved in hot water, and the free acid is precipitated by theaddition of hydrochloric acid;

. The 3-hydroxydiphenylenesulfide 2 carboxylic acid of the formula:

S/ oooH crystallizes from pyridine in yellow needles of the meltingpoint 283 C. Its alcoholic solution yields a powerful blue coloration onthe addition of ferric chloride. I 1

Example 2.21 parts by weight of 3-hydroxydiphenylenesulfone aretransformed into the potassium salt and treated with carbon-dioxideunder superatmospheric pressure and at elevated temperature as describedin Example '1.

The working up is performed according to the directions given inExample 1. The 3-hydroxydiphenylenesulfone-2-carboxylic acid of theformula:

weightv of 3-bromodiphenylenesulfone with parts by weight ofcrystallized barium hydroxide, 20 parts by weight of copper oxide and250 parts by Weight of water in'an autoclave at 220 C. for 2 4 hours,boiling the reaction product repeatedly with water, filtering theextracts and acidifying the filtrates with hydrochloric acid.

In analogous manner as described in paragraph t l the3-hydroxydiphenylenesulfoxide yields the3-hydroxydiphenylenesulfoxide-2-carboxylic acid and corresponding to thefollowing formula:

\SO/ OOOH The 3-hydroxydiphenylenesulfoxide is obtainable by dissolvingS-aminodiphenylenesulfoxide in hot technical phosphoric acid, coolingthe solution to 0-5 C., diazotizing in the usual manner with aqueoussodium nitrite solution, and dropping the diazo solution into a flaskheated at -200? 0., thereby simultaneously passing through that flasksuperheated steam of ISO-200 5 690,951, filed September 25, 1933.

I claim:

The hydroxy carboxylic acid of diphenylene- 0 sulfide which is obtainedby causing carbon dioxide to react upon 3-hydroxy-diphenylenesulfide inthe presence of an alkali, said compound being a yellow crystallinesubstance of a melting point of 283 C.

FRIEDRICH MUTH.

